1. Field of the Invention
This invention relates to a device for controlling the absorption of at least one color component contained in a dyeing fluid by regulating the temperature dependent on the transparency of the dyeing fluid, wherein the temperature is set each time at the optimum value for the absorption operation.
2. Description of the Prior Art
In a prior art device for the dyeing of textile material, a shunt circuit provided with a transparent section is connected to a dye tank. A pencil of rays penetrating this section is directed to a photo-electric receiver, the outgoing signals of which are a measure of the light transmitting quality of the dyeing fluid. In order to achieve a favorable attaching operation or absorption, the temperature is kept constant during changes in transparency, and the temperature is increased when the transparency is constant. A limit value of transparency indicates that all color components are absorbed.
In another prior art device, a pencil of rays likewise penetrates a transparent portion of a shunt circuit and is then directed to a photo-electric receiver. The outgoing signals of the latter are then transmitted to a logarithmic amplifier, so that not the transparency but rather the concentration of the dyeing fluid is determined and used for controlling the dyeing operation.
Both devices have the disadvantage that dispersion influences of the coloring substances adversely influence the measuring operation and thus the contol of the dyeing operation. Especially in light dyeing fluids, due to dispersion, the transparency and concentration are not correctly defined and the dyeing operation is adversely influenced. Complicated calibrating processes and the use of color filters are required in order to be able to reduce the errors due to such dispersion influences.